Device for straight-line slitting and cutting of corrugated paper

ABSTRACT

A device for cutting corrugated paper including one or more disc-like knives fixed to a rotatable shaft. The circumference of each knife enters a groove in a table over which the paper travels with the paper held on the table by connection of the groove to a suction device. Very small clearance is provided between the rear edge of the groove, which edge is reinforced by a plastic strip, and the circumference of each knife to obtain a positive cutting action.

United States Patent Schneider Mar. 5, 1974 [54] DEVICE FOR STRAIGHT-LINE SLITTING 3,465,625 9/1969 Daly 83/100 AND CUTTING 0 CORRUGATED PAPER 3,293,962 12/1966 Gianaris.. 83/332 3,494,232 2/1970 Lindau 83/100 Inventor: Rudolf Schneider, g, 3,156,149 11/1964 Frizellc 83/100 x Germany 1,939,925 12/1933 Schwartz 83/100 [731 Assigneei fi s"?! gmmgated Machinery, FOREIGN PATENTS OR APPLICATIONS u ec emany 985,083 3/1965 Great Britain 83/508 [22] Filed: June 8, 1972 [21] Appl. N0.: 260,845 Primary Examiner-Roy Lake Assistant Examiner lames F. Coan F B & B l Foreign Application Priority Data Attorney, Agent, or zrm eaman eaman June 19, 1971 Germany 7123640 [57] ABSTRACT 52 1 3 83 100, 425.4, I 1 U S C 2 632} 2 A device for cutting corrugated paper 1nclud1ng one [51] Int Cl B26d b or more disc-like knives fixed to a rotatable shaft. The [58] Fieid 2 425 3 circumference of each knife enters a groove in a table 83/425 4 331 over which the paper travels with the paper held on 508 594 1 95/58 the table by connection of the groove to a suction de- 5821, 'd vice. Very small clearance is provided between the rear edge of the groove, which edge is reinforced by a [56] Reerences Cited plastic strip, and the circumference of each knife to UNITED STATES PATENTS obtain a positive cutting action.

2,003,404 6/1935 Valentine 83/100 3 Claims, 2 Drawing Figures DEVICE F OR STRAIGHT-LINE SLITTING AND CUTTING OF CORRUGATED PAPER BACKGROUND OF THE INVENTION The invention relates to a device for the straight-line slitting and cutting of corrugated paper.

Corrugated paper is produced inplants for manufacturing corrugated paper in broad webs up to 2.65 m. wide at the present time. In these plants, the webs are first cut lengthways and then cross-cut to subsequent production sizes.

It is a standard procedure at the present time to cut up the broad web into narrower webs by means of rotating circular knives, which are fastened by appropriate knife holders to a pair of cutter spindles. The cut is made in the manner of a scissor cut in that the knives slice through the web from both sides.

The knives which operate as upper and lower blades must be exactly flat against each other and be true, in order to obtain a satisfactory cutting edge. There must also be a specific contact pressure on the cutting surfaces of the knives. These cutting requirements call for highly precise and careful setting of the knives. When setting is by hand, it is very time-consuming and, when done automatically, a complex and expensive mechanical and electronic investment is required, since the cutting tools to be set are located both above and below the web.

An object of the invention is to simplify the setting of the straight-line slitting and cutting tools.

SUMMARY OF THE INVENTION According to the invention the cut is made using only one thin, rotating knife, which penetrates a groove in a frame member supporting the web of corrugated paper, the edge of the knife being separated by only a small clearance from that edge of the groove which is to the rear, considered in the direction of the oncoming web of corrugated paper.

Thus, the circumference of the thin knife, moving with a high degree of lead, penetrates the groove, however, only approaching said rear edge until there is a very small clearance, which, on the one hand, ensures the straight-line slitting and cutting-through of the web of corrugated paper through its entire thickness and, on the other, prevents any damage to the circumference of the thin knife.

A plurality of spaced knives may be provided, the knives themselves being fixed on their driving shaft so they cannot rotate on it, although they are axially adjustable, e.g. by means of a tongue-and-groove joint.

In this way, both manual setting and automatic setting of such cutting devices are simplified. The web of corrugated paper is slit and cut satisfactorily through its entire thickness, without there being the risk of the waves in the web of corrugated paper pressing together at the slitting and cutting edge.

Preferably said rear edge of the groove is strengthened by means of an elastic strip, made out of a synthetic plastics material and/or rubber. Thus, in the area of the cut, there is a satisfactory and sufficiently firm support for the web of paper to be cut, without there being the risk of any damage to the knife.

The groove may be connected to a source of vacuum via a pipeline. In this way, the paper dust and the remnants of paste and paper which result from the cutting process are immediately drawn off and removed at their point of origin.

The front edge of the groove, with respect to the direction of movement of the web of paper, may be fitted with a sheet-metal guide running across the groove, which prevents the web of corrugated paper from dropping into the groove.

Any edge strips which occur can be extracted in the normal manner via laterally adjustable nozzles. These laterally adjustable nozzles may be connected to a holder supporting a stay plate, which prevents the edge strips from falling into the groove at the rear edge thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic representation of a device for cutting corrugated paper, embodying the invention described.

FIG. 2 is a diagrammatic perspective view of the straight-line slitting and cutting device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS To simplify the setting of the tools and insure a longer life for the knives, the web of corrugated paper 11 is completely out through from one side by thin knives 2, which have either a smooth cutting-edge or may be saw-toothed, as shown in FIG. 2. The number of knives may be varied as required. The web of corrugated paper 11 is supported on the opposite side by a frame member 3.

This frame member 3 has on the side facing the knife an opening or groove 4 into which the knife penetrates. The rear edge 12 of the frame member 3, as seen from the direction of the oncoming web of corrugated paper 11, is re-enforced by an elastic strip 5, of synthetic plastics material or rubber, in order to prevent the cuttingedge from being harmed. As can be seen from FIG. 2, the cutting edges of the knives 2 are situated very close to edge 12 of the frame member 3.

A vacuum acts upon the frame member 3 via a pipeline 14, so that the moving web of corrugated paper II lies flat against it and, at the same time, the dust and cuttings produced by the cutting operation are extracted. In order to prevent the front edge of a new web from being drawn into the groove 4, there is an appropriately formed sheet-metal guide 6 on the front edge of the frame member 3. This sheet-metal guide 6 runs across the entire width of the groove 4.

Edge strips 13 of the corrugated paper, resulting from the apportioning of the web into a number of widths, are drawn off in the normal manner via appropriately shaped, laterally adjustable nozzles 9. To prevent any loose edge strips from being drawn into the groove 4, each nozzle 9 is fitted with a holder 8 which supports a stay plate 7, made of spring steel, for exam ple. This stay plate 7 is laterally adjustable with the associated nozzle. Another stay plate 10 is fastened to each nozzle 9, so as to avoid damage to the moving web 11 by the rims of the nozzles.

As shown in FIG. I, the web of corrugated paper is supplied to the knife attachments 15 in an undivided state and leaves them in the form of sectioned webs. Each cutting device, 2, 3 has a plurality of straight-line slitting and cutting knives 2, arranged parallel to each other across the web of corrugated paper.

FIG. I shows that, in front of the slitting knives 2, a pair of grooving devices 17 are provided, which groove the corrugated paper in the normal manner. Although the grooving process is carried out within the framework of the cutting device, it forms no part of the present invention and no more details are accordingly given about the pair of grooving devices 17.

As also shown in FIG. 1, there are two cutting devices, arranged behind one another in the direction of movement of the web of corrugated paper. While one of the cutting devices, such as the cutting device 16, is in operation and is acting upon the web of corrugated paper, the other cutting device is out of operation, as a result of which its knives 2 and its pair of grooving devices 17 can immediately be set for further work.

What is claimed is:

1. Apparatus for slitting elongated webs of corrugated paper moving in the direction of the length of the web comprising, in combination, a rotatably driven shaft having a substantially horizontal axis of rotation, at least one disc knife mounted on said shaft for rotation therewith having a circular cutting periphery, an elongated frame member disposed below said driven shaft having a front upward extending wall terminating in an upper end having a rear linear edge substantially parallel to said shaft axis, said frame member including a rear upwardly extending wall spaced from said front wall in the direction of web movement relative to said frame member and having an upper end, said front and rear walls and said upper ends thereof defining a table for supporting the web to be slit and forming an elongated opening substantially parallel to the axis of said shaft and vertically below said shaft and opening upwardly toward said shaft of a length corresponding to the length of said frame member, said front wall rear linear edge being disposed at a vertical elevation higher than the lowermost portion of said disc knife wherein said knife extends downwardly into said opening, the lowermost periphery of said knife moving in the direction of web movement and said knife periphery being closely spaced to said front wall rear linear edge whereby said rear linear edge supports the web to be slit adjacent the location of initial engagement of said knife periphery with the web.

2. In an apparatus for slitting elongated webs of corrugated paper as in claim 1, a strip of elastic material aflixed to said front wall end defining said rear linear edge.

3. In an apparatus for slitting elongated webs of corrugated paper as in claim 1, a guide mounted upon said frame member within said opening and extending the length thereof, said guide being mounted on said rear wall adjacent the upper end thereof and extending downwardly and toward said front wall for deflecting slit web material from entering said opening. 

1. Apparatus for slitting elongated webs of corrugated paper moving in the direction of the length of the web comprising, in combination, a rotatably driven shaft having a substantially horizontal axis of rotation, at least one disc knife mounted on said shaft for rotation therewith having a circular cutting periphery, an elongated frame member disposed below said driven shaft having a front upward extending wall terminating in an upper end having a rear linear edge substantially parallel to said shaft axis, said frame member including a rear upwardly extending wall spaced from said front wall in the direction of web movement relative to said frame member and having an upper end, said front and rear walls and said upper ends thereof defining a table for supporting the web to be slit and forming an elongated opening substantially parallel to the axis of said shaft and vertically below said shaft and opening upwardly toward said shaft of a length corresponding to the length of said frame member, said front wall rear linear edge being disposed at a vertical elevation higher than the lowermost portion of said disc knife wherein said knife extends downwardly into said opening, the lowermost periphery of said knife moving in the direction of web movement and said knife periphery being closely spaced to said front wall rear linear edge whereby said rear linear edge supports the web to be slit adjacent the location of initial engagement of said knife periphery with the web.
 2. In an apparatus for slitting elongated webs of corrugated paper as in claim 1, a strip of elastic material affixed to said front wall end defining said rear linear edge.
 3. In an apparatus for slitting elongated webs of corrugated paper as in claim 1, a guide mounted upon said frame member within said opening and extending the length thereof, said guide being mounted on said rear wall adjacent the upper end thereof and extending downwardly and toward said front wall for deflecting slit web material from entering said opening. 